Jlf4+z UDC 001'4 : 629'73/`78'036 qw(" "RE-AFFlRM ED 1997' IS : 7879 [ Part 8 I- 1987 i`y- " m qic:R :\,-La _ `_ i -..i ( Reaffirmed 2005 % ) XL \. , > \ Indian Standard GLOSSARY OF AERONAUTICAL PART 8 AND ASTRONA"Tl&i$iii'/~~ PLANT ._ POWER 1. scope - Covers terms and definitions relating to gas turbines and jet propulsion SECTION No. 8101 Composite Term engine 81 relating to power plant for aerospace are covered in separate sections. OF POWER Definition PLANT applications. Terms MAIN CLASSES A combination of two engines of basically different thermodynamic cycles, such as a piston-turbine engine combination. Not to be confused with the general engineering term `compound engine'. An engine in which the working fluid is heated combustion and expanded through a turbine. by internal 8102 8103 8104 8105 8106 Gas-turbine Jet engine Lift engine Piston engine engine Any engine that ejects a jet or streams of gas or fluid, obtaining all or most of its thrust by reaction to the engine, An engine used primarily or STOL aircraft. to provide lifting force on a VTOL in a cylin- An engine in which the working fluid der against a reciprocating piston, is expanded Ramjet engine AEROTHERMODYNAMIC DUCT ( ATHODYD ) Rocket ramjet An engine producing a jet by burning fuel in air which has been compressed, by forward speed alone, in an appropriately shaped duct and expanded in a nozzle. A ramjet engine having a rocket attached to it, usually mounted concentrically within the ramjet duct, the rocket being used to bring the vehicle up to the necessary operating speed for the ramjet. A device for producing thrust by the ejection of matter, usually in gaseous form, the thrust being generated from propellant carried in the system. An engine in which nuously varied. the direction the of main thrust can be contior lifting 8107 8108 Rocket motor 8109 8110 Vectored thrust engine AIRCRAFT SECTION Aero-engine ENGINE An engine used to provide power for an aircraft. 82 TYPES OF PISTON propulsive ENGINE forming, arranged in end view, parallel to 8201 8202 8203 8204 Arrow Axial engine engine ignition An engine with three rows of cylinders a broad arrow. An engine with the axes of its cylinders the driving shaft. Compression engine H-engine An engine in which ignition of the working fluid in the cylinder is produced by the heat of compression alone. An engine letter `H'. with its cylinders forming, in end view, the Adopted 16 January 1987 I 0 January 1988, BIS I Gr 7 BUREAU MANAK OF BHAVAN, INDIAN STANDARDS ZAFAR MARG 9 BAHADUR SHAH NEW DELHI 110002 IS : 7879 (Part 8) - 1987 No. 8205 8206 8207 In-line Inverted Opposed Term engine engine cylinder engine An engine to rear. Definition with its cylinders its cylinders arranged in bank(s) from front An engine with below the crankshaft (Cf 8215). An engine with its cylinders arranged opposite each other in the same plane, their connecting rods working on the same crankshaft. An engine cylinder. with two pistons acting in opposition in the same 8208 8209 Opposed-piston Radial engine engine An engine with a row, or rows, of cylinders round a common crankshaft, the cylinders and the crankshaft revolving. engine A radial engine spaced radially being stationary 8210 8211 Multi-row Rotary radial engine with two or more rows of cylinders. equally spaced round a common being stationary and the cylind- An engine with its cylinders crankshaft, the crankshaft ders revolving. engine 8212 Supercharged An engine in which the charge pressure in the induction system may be creased, by mechanical means, above that produced by normal aspiration. An unsupercharged engine of high compression ratio which is designed not to be run at full throttle except at or above some predetermined altitude. An engine letter `V'. with its cylinders forming, in end view, the 8213 Supercompression engine V-engine Vertical X-engine engine 8214 8115 8216 Engine An engine with its cylinders ( Cf 8206 ). A;etn;i;P 1 . with vertically forming, above in the crankshaft end view, the its cylinders Components Location of Parts The following are the standard adjectives for the location of parts, the engine being assumed normal running position with the observer looking along it towards the output shaft end: Left Front Top 8217 Flame trap INDUCTION DAMPER FLAME Centre Middle Centre Right Rear Bottom in A device fitted in the induction system to prevent the passage of flame in the event of a `backfire' or `blow-back'. A ring for maintaining a gas-tight seal between the cylinder head and the bore of sleeve valve. The detachable engine. short end of a crankshaft one or in a rotary or radial connecting rods 8218 8219 8220 8221 Junk ring SEAL RING/GASKET Maneton piston connecting Connecting rods rod assembly The complete assembly of working on one crankpin. more Forked assembly An assembly of connecting rods in which one carries the big end bearing and the remainder encircle and oscillate upon a surface formed on the master rod or big-end bearing concentric with the letter. An assembly of connecting rods in which the big-end of the. master rod carries the articulated rods oscillating on wrist pins and held in lugs or flanges on the master rod. 2 8222 Master and assembly articulated IS:7879 No. 8223 Term Side-byside assembly An Definition (Part 8)- 1987 assembly of connecting rods in which a number of similar plain connecting rods are arranged successively side-by-side with narrow big-ends usually carrying roller bearings. 8224 Slipper-type assembly An assembly of connecting rods in which each rod has a slipper held in,place by flanges, riding on the outer surface of the big-end bearing, or in an annular groove. A spring ring for maintaining piston and cylinder wall. A gas ring L-shaped A spring wall. a gas-tight seal between the 8225 8226 8227 8228 Piston rings gas ring (COMPRESSION RING) Obturator ring in cross section. superfluous oil from connecting the cylinder Scraper ring ( OIL RING ) Wrist-pin (KNUCKLE PIN LINK PIN) ring for removing attaches The pin which master rod. an articulated rod to the Carburation 8229 Accelerator pump A mechanism the opening A device which predetermined boost which temporarily of the throttle. enriches the mixture with 8230 8231, Boost control Variable-datum control Boost control so regulates the manifold value is not exceeded. pressure that a A boost control in which the controlled manifold pressure varies progressively with the position of the hand throttle lever. A device to override the boost control higher than the normal controlled obtained. so that a pressure pressure can be 8232 override 8233 Boost pressure The pressure in the induction system at a point standardized for each type of engine, expressed as an amount above or below the standard sea-level atmospheric pressure ( See Manifold pressure ) A carburettor air stream cylinders. which injects the fuel at some point before under pressure into the it is distributed to the out the same functions the fuel direct into the 8234 Bulk-injection carburettor ( PRESSURE INJECTION CARBURETT~R ) Bulk-injection Direct-injection Float-type pump pump 8235 8236 8237 8238 8239 8240 A fuel metering pump which carries as a bulk injection carburettor. A fuel metering pump which individual engine cylinders. injects carburettor A carburettor in which the head of the fuel supplied jet is controlled by a float and needle valve. to the Fuel trimmer Induction manifold A mechanism which adjusts the fuel to air ratio for a given throttle setting under different ambient conditions. A branched a number pipe for distributing of cylinders. the air or airfuel mixture to Intercooler AFTERCOOL ER A component installed on the delivery side of a supercharger or compressor to cool either the compressed air or the airfuel mixture. ( It is normally driven by engine or by a turbine.) A"device embodied in the fuel metering the mixture strength. A device for varying, in accordance sity, the quantity of fuel delivered. 3 system for adjusting in air den- 8241 8242 Mixture Automatic control control mixture with changes IS : 7879 ( Part 8 ) - 1987 No. 8243 8244 8245 Power Term boost Definition A device or system fdr increasing temporarily the power of an engine above its normal maximum continuous rating. A device for cutting The injection agent such detonation. of as off the supply of metered fuel. Slow-running cut-off FUEL CUT-OFF Water-injection water, usually mixed with an anti-freeze methanol, into an engine to suppress Superchargers 8246 Supercharger A compressor used to increase the density of the air or mixture supplied to an engine. Normally driven either by the engine or by an exhaust turbine. A supercharger in which the air or mixture an axial flow compressor. A supercharger a centrifugal in which the air or mixture compressor. in which is compressed is compressed gear by by 8247 8248 8249 8250 8251 8252 8253 Axial-flow Centrifugal Multi ger super charger supercharger supercharsupercharger speed A gear driven supercharger may be engaged. A supercharger series. having alternative ratios in Multi-stage two or more stages of compression volumes of air or mixture Positive-displacement supercharger Roots supercharger Vane supercharger in which A supercharger ted and compressed. are isola- in nwhich compression is effected by the relaA supercharger tive motion of two meshing rotors in a fixed case. A supercharger in which compression is effected by the motion of vanes carried in a rotor accentrically located in a fixed case. Exhaust 8254 8255 System Exhaust manifold A pipe or chamber into which number of cylinders. An exhaust engines. manifold exhaust gases are led from used in radial a Collector ring ( CQLLECTOR Exhaust pipes Branch pipe in the form of a ring, ) 8256 8257 8258 A short pipe which conveys an exhaust manifold. A pipe so disposed forward thrust, exhaust gases from a cylinder as to produce appreciable to Ejector pipe Stub pipe or shapped A short pipe which discharges the exhaust gases directly from a cylinder directly to atmosphere in theabsence of a manifold. A pipe which leads exhaust visual gases away from a manifold. detection of an aircraft vision by its exfrom being . 8259 8260 8261 8262 8263 8264 Tail pipe Flame damper Glare shield Glow screen Heating Intensifier muff tube A device to prevent haust flame. A device to prevent impaired by exhaust for obscuring the pilot's night flames or flow. the glow from A devide hot metal. pipe or manifold, to A chamber, surrounding provide hot air, an exhaust A tube inserted in an exhausted manifold for the purpose of heating air passing through the tube and conveying it to a carburettor for de-icing or anti-icing. 4 , IS : 7879 ( Part 8 ) - 1987 No. Ignition 8265 8266 8267 8268 System Booster Impulse Isolating Screened coil starter spark gap ignition An induction coil providing a spark to facilitate starting. to the Term Definition A mechanical device which gives a series magneto to facilitate starting. A spark gap in the H. T. booster from the magneto. of impulses lead to prevent feed-back An ignition system in which all components are surrounded by an earthed metallic screen to prevent radio interference therefrom. Cooling 8269 8270 8271 8272 8273 8274, 8275 8276 8277 8278 8279 8280 8281 8282 System Ducted coolant cooling radiators engine A system in which cooling air is constrained or ducts to or from the power plant. A radiator shaped to fit within a circular which the cooling air flows axially. A radiator A radiator coolant A surface wing. installed consisting circulates. radiator in a duct. of a block of tubes which forms between which the to flow in a duct and through Annular radiators annual radiator Ducted radiator radiator radiator radiator cowling Honeycomb Leading-edge Mixed matrix Nose radiator Ring radiator Secondary tor Series Surface part of the leading edge of a A radiator compounded with an oil cooler tubes are used for coolant and oil. A radiator fitted at the front form of an fuselage through increased in front which so that alternate or nacelle. the cooling air A radiator of circular flows radially. radiaA radiator A ducted surface with the cooling radiator mounted by fins. radiator radiator radiator of an oil cooler. of the aircraft A radiator in which some part of the surface is adapted for cooling. A radiator A radiator fitted below a wing. in a wing. Under-wing Wing radiator located Evaporative cooling A cooling system which utilizes the latent heat of evaporation by allowing the coolant to boil and, aftercondensation, to return to the cylinder jackets. A set of movable flaps at the rear of a cowling flow of cooling air. LUBRICATION, FUEL SYSTEM AND STARTERS to control the 8283 Gills COWLLING SECTION GILLS 83 Lubrication 8301 8302 8303 8304 8305 System A cooler A cooler incorporated installed in an air intake. Lubricating oil coolers air-intake oil cooler Ducted oil cooler oil cooler oil cooler in a duct. with a radiator and oil. so that alternate units. tubes Mixed-matrix Multi-element A cooler compounded are used for coolant A cooler composed A ducted of a number behind of cooling a radiator. Series oil cooler cooler mounted 5 IS : 7879 ( Part 8) - 1987 No. 8306 8307 8308 Surface Term oil cooler Definition A cooler in which some part of the surface adapting for cooling. A cooler and oil tank combined. the performance of an oil thermostatic or anti-surge be diluted to assist cold of the aircraft is Tank oil cooler Oil control valve An automatic valve to regulate cooler, e. g., by-pass, viscosity, valve. A system starting. by which oil the oil can 8309 8310 8311 8312 8313 8314 Oil dilution Food pipes Scavenge system Pipes leading ssory. pipes from the oil tank to the engine or acceto the Return pipes leading oil tank. oil from the engine or accessory Tank vent pipe Pumps pressure Scavenge pump pump A pipe leading from the air-space pheric or engine casing. A pump which accessory. supplies in an oil tank to the atmosto the engine or oil under pressure A pump which withdraws used oil from the engine sory and returns it to the oil tank. oracces- Fuel System 8315 8316 8317 8318 Avcat Avgas Avtag Avtur An aviation flashpoint. An aviation An aviation An aviation turbine gasoline. turbine turbine wide cut gasoline, fuel of the kerosene type. maximum fuel of the kerosene type with a high of a figure after the term avcat or avtur gives an indication Note - The addition point, e.g. avcat/40 is an avcat which has a freezing point not higher than -40°C. of the freezing 8319 8320 8321 8322 8323 8324 8325 8326 8327 8328 8329 Booster pump A fuel pump pipe. used to maintain positive pressure in `a feed in Float mechanism Fluid level indicator gear tank A float operated a fuel system. mechanism for control of a valve located of the level A device which gives a remote indication fuel in a tank of an aircraft. Gear for the rapid discharge A removable be carried. An external tank in which tank designed of the Fuel-jettison Fuel Tanks Auxiliary Drop tank Gravity Integral tank tank of fuel in emergency. an additional to dropped supply in flight of fuel can when empty. by A tank from which gravity alone. Part of the structure tank tank switch A tank which thP fuel is supplied of the aircraft to the engine(s) adapted to form a tank. Jettisonable Semi-integral Inverted flight can be jettisoned in emergency. structure to a fueifuel flow A detachable tank which when in place. forms part of the aircraft A mechanically operated switch breaks the circuit no-air valve or similar component to interrupt from tank to engine during inverted flight. 8330 Recuperator A vessel in which fuel is stored so as to meet negative acceleration conditions, the fuel being fed into the engine by application of air pressure. 6 IS:7879(Part No. 8331 Sloshing Valves 8332 Double shut-off valve Term Definition 8)-1987 Movement to and fro of liquid in its tank, which may adversely affect stability and control of a flying vehicle. A valve incorporating two separate and indepedently controlled shut-off devices so that if one fails to operate the other shuts off the flow. A device which ensure that, when an engine receives fuel from a pressurized tank, fuel only is admitted to the fuel inlet of the engine regardless of the attitude of the aircraft air or other gases used for pressurizing being excluded. A valve which emergency. permits the discharge of fuel pressure overboard in 8333 Fuel-no-air valve 8334 8335 8336 Jettison Pressure valve Transfer valve maintaining valve A valve which maintains a particular system for some special purpose. in part of the A valve which enables fuel to be transferred from one tank to another, particularly during flight. Usually so arranged that, when the fuel in a tank falls below a predetermined level, the valve opens and admits fuel from another tank. restrictor A valve which permits free flow in restricts flow in the reverse direction. one direction but 8337 Unidirectional valve and Guards Air In takes Air Intakes 8338 Centre-body intake An air intake whose air duct is formed between an outer skin and inner member known as the centre body, which may be axially movable. An air intake for supersonic operation in which the greater part of the compression occurs in one or more shocks at and upstream of the intake lip. An air intake for supersonic operation in which the greater part of the compression occurs in one or more shocks within the intake. An air intake for supersonic operation occurs in a number of shocks. in which compression on intake air 8339 External compression 8340 Internal intake Multi-shock compression 8341 8342 8343 8344 8345 8346 intake intake Non-ramming Ramming Single Variable Wedge An air intake in which the effect of forward air pressure is neutralized. An air intake pressure. directed forward to increase speed intake the intake shock intake geometry intake intake An air intake for supersonic occurs in only one shock. operation in which compression in flight. form, of one An air intake whose area or shape can be varied A variable geometry intake, usually of rectangular whose area and shape are defined by the position or more variable ramps. A casing through which the air is admitted 8347 Air intake casing to the engine. Filters 8348 8349 8350 Air filter ( AIR CLEANER Filter element filter element An assembly ) A replaceable component from a fluid stream. for removing filter, entrained particles Is of filter elements in the air intake. Dry-type A filter element in an air effected by a dry matrix. 7 in which ihe filtration IS : 7879 ( Part 8 ) - 1987 No. 8351 8352 Wet-type Momentum Guards 8353 Ice guard A screen fitted to an intake to provide a surface for the adhesion of ice and so prevent its serious accretion in the air intake system. ice guard ice guard An ice guard fitted in the intake mouth, used with an automatic alternative air Inlet. in conjunction entry to Term filter element Definition A filter element in an air effected by a liquid film. filter, in which from the filtration the air stream is by separation The removal of entrained particles utilizing their momentum. 8354 8355 8356 8357 Gapless-type Gapped-type An ice guard mounted forward of the air intake provide a gap which does not ice up. A device for raising ing the engine. the temperature of the intake intake, Intake air heater Plenum chamber air entersupplying A chamber, usually fed from auramming air to the engine or for other purposes. Engine 8358 Starters Cartridge starter A device in which the gases generated in a cartridge are used to rotate an engine for sta.rting. The cartridge may contain an explosive charge, compressed gas or volatile liquid to rotate the compressor for starting the engine. A device in which the hot gases from the combustion of fuel are used to rotate an engine for starting, either directly or by coupling on to a shaft. A device for starting an engine by utilizing the expansive energy of compressed air stored in the cylinders or otherwise. An electric Any device, engine. motor used to rotate an engine in an aircraft, for starting, an aero 8359 Combustion starter 8360 Compressed air starter (PNEUMATIC STARTER) Electric Ground starter starter 8361 8362 8363 not carried for starting Hand starter in an aero-engine or attached thereto, A device, embodied for rotating the engine by hand, otherwise than by the propeller, for starting. A device by which energy is stored in a small high speed flywheel and, for starting, transmitted to an engine through a slipping clutch, the flywheel being energized either by hand or otherwise. An internal combustion engine used tostart the main engine. 8364 Inertia starter 8365 8366 Internal-combustion starter Turbo-starter gTiSTURBINE Terminology Accessory Auxiliary Bootstrap Consumption gearbox power unit APU STARTER) A starter incorporating a small turbine energized by compressed air or other gas, with or without combustion. General 8367 8368 8369 8370 An engine driven gearbox for driving accessories. equipment to provide to be An independent engine and ancillary power for auxiliary services. Applied to a self-sustaining process which needs started in operation by outside power or propellant. The total quantity 8 of fuel or oil consumed per hour. IS : 7879 ( Part 8 ) - 1987 No. 83 71 Specific Term consumption Definition 1. Of engines driving propellers : The quantity by weight fuel or oil consumed per horsepower per hour. 2. Of jet reaction engines: consumed per kilogram 8372 Cooling Film cooling Regenerative cooling of The weight of propellant or fuel ( Newton ) of thrust per hour. chamto the Evaporative cooling of the inner wall of a combustion ber or other surface by a coolant injected adjacent surface. The process of cooling by the circulation enabling some heat, otherwise wasted, 8373 8374 of fuel or oxidant, to be recovered. passes evenly of Sweat cooling (TRANSPIRATION COOLING) Cowl flap Cowling Non-pressure cowling ( SEALED COWLING ) Pressure cowling (UNSEALED COWLING Engine rating ) Evaporative cooling in which the cooling liquid through a porous wall and is thereby distributed over the surface to be cooled. A shutter cooling in an aircraft cowling, used to regulate air around the engine. 8375 8376 8377 8378 8379 the flow A cover surrounding the whole installed in an aircraft. A cowling designed to prevent the engine nacelle. or part of a power unit entry of surrounding when air into A cowling in which the pressure either by ram effect or by a fan. of the air is increased, A statement of the specified . . .minimum . . output. _( horsepower or thrust ) under prescribed Conditions and for a prescribed period. rating A special rating for power or thrust usable in emergency for particular classes of aircraft or conditions of flight and duration. This is the highest rating of the engine which may be used This rating for a prescribed period of time in each flight, can include the use of reheat or bypass heat, This is the highest for an unlimited to the authorised rating of the engine which may be used duration in each flight without detriment life of the engine. 8380 Contingency 8381 rating RATING, RATING KI?KZ!!Y WITH REHEAT ) Intermediate Normal continuous rating 8382 8383 Maximum rating Maximum continuous The highest rating of the engine which may be used during periods of unrestricted duration, but use of this rating may be detrimental to the authorised life of the engine, The maximum thrust that may be raised by a vectored thrust engine for a prescribed time during vertical or short takeoff or landing. The maximum thrust for a prescribed time in a vectored thrust engine which can be used at times other than during vertical take-off or landing. The boundary of a burning zone in a combustible fuel-air mixture, mixture. designed to 8384 lift rating 8385 Maximum thrust engine 8386 8387 8388 Flame front Flame holder ( FLAME STABILIZER Height power factor ) A device inserted in a moving stabilize a flame. The ratio of the power or thrust developed at a specified altitude to that which would be developed at standard sea level. It applies to maximum power or thrust conditions at full throttle. Two completely 9 independent engines mounted close together. 8389 Paired engines IS : 7879 ( Part 8 ) - 1987 No. 8390 Term Power unit Definition An engine or assembly of two or more engines, as fitted into an aircraft, complete with all components and accessories. power power (or clockwise) (or clockwise) A power unit containing common shaft. A engines two coupled engines together driving to drive a co-axial the 8391 8392 8393: 8394 8395 Coupled-engine unit Double-engine unit Right-hand accessories Right-hand drive Weights power unit propellers. containing An accessory rotating clockwise to an observer facing driven end, to mate with an anti-clockwise drive. A ,";Fe rotating clockwise to an observer facing the driving dry weight The weight of an engine without liquid, but including all accessories essential to its running and any drives incorporated in it for non-essential accessories. The dry weight of an engine ssible horsepower, divided by its maximum permipermi- 8396 8397 Weight Weight per horsepower per bound thrust The dry weight of an engine divided by the maximum ssible thrust under standard sea level conditions. TURBINES ( Location AND JET PROPULSION SECTION 84 GAS of Parts ) The assumed following in normal Left Front Top are the standard adjectives for the location of parts, the engine being running position with the observer looking along it towards the intake: Centre Middle Centre Right Rear Bottom TYPES OF GAS TURBINE 8401 AND TURBINE COMPONENTS fuel is injected engine, reheat- Afterburner Gas Turbines A combustion chamber in which additional into the hot exhaust gases of turbine type ing them and developing increased thrust. turbine turbine A turbine through which the general direction 8402 8403 8404 Axial-flow Compressor Impulse of flow is axial. as distinct from The turbine which drives the compressor that which drives an output shaft. turbine A turbine in which the whole of the pressure drop ing fluid expansion occurs in the fixed nozzle passages. or workor blade 8405 Inward-flow turbine A turbine in which the general direction of flow is radially inwards with axial outlet, and the pressure drop in the working fluid is caused largely by the action of centrifugal force during passage through the rotating member. A turbine which functions by the action of the working fluid on rows of rotating blades in conjunction with nozzles, or rows of fixed blades, the general direction of flow being radial. A turbine in which the whole or part of the pressure drop or working fluid expansion occurs in the moving blade passage. A combustion-chamber unit stages, to provide additional 10 situated power. between the turbine 8406 Radial-flow turbine 8407 Reaction turbine 8408 Interheater IS : 7879 ( Part 8 ) - 1987 NO. Term Main rotor Nozzle Turbine Turbine guide disc entry duct ring Definition The complete assembly ssor and turbine. of the rotating parts of the compre- 8409 8410 8411 8412 8413 A ring of stationary guide-vanes which accelerate the gas and direct it onto a row of rotating turbine blades. The rotating member turbine are carried. A duct leading of which the blades of an axial-flow to the turbine. the products of combustion Turbine rotary shroud TURBINE TIP SHROUD Turbine static shroud TURBINE SHROUD RING Turbine wheel A complete or segmented band mounted on the tip of the rotor blade, sometimes formed by lips projecting tangentially from the blade tips. A ring used to prevent the escape of gas past the tips of the blades in an axial flow turbine. The assembly comprising a turbine disc and blades. 8414 8415 Compressor 8416 Axial System flow compressor A compressor in which the air is compressed by its passage axiajly past rows of blades alternately rotating and either fixed or contra-rotating. A compressor in which the compression passage of the air radially outwards and into a diffuser. A rotary compressor through is partly radially and partly is initiated by the through an impeller of fluid only 8417 Centrifugal compressor 8418 8419 8420 8421 8422 Mixed-flow Single-entry Double-entry Compressor compressor compressor compressor which the acceleration axial. A compressor in which the air is admitted to one side of the impeller, or at one end of the rotating member. A compressor in which air is admitted to both sides impeller, or to both ends of the rotating member. A passage through which compressed air is ducted from the compressor to perform an auxiliary service. of the away bleed blow off Compressor An arrangement to discharge air from any stage of a compressor to prevent the compressor stalling when operating away from its design conditions, e.g. during acceleration. A casing enclosing the impeller or rotating member. 8423 8424 Compressor Compressor casing diffuser A ring of fixed vanes, or one or more expansion passages, situated in the compressor delivery to assist in the conversion of the kinetic energy of the air into pressure energy. A cylinder, or series of connected discs, upon which the rotating blades of an axial-flow compressor are mounted, A compressor, or part of a compressor, consisting of one row of rotating and one row of fixed blades in an axial-flow machine or one impeller and its associated diffuser in a centrifugal machine. A condition in a rotary air compressor in which some of the blades or vanes of some stages meet the air flow at such an angle that the flow is distributed which may lead to break down or discontinuity of flow and unsatisfactory operation of a gas turbine engine. The rotating member of a centrifugal sultably shaped vanes. compressor, carrying 8425 8426 Compressor Compressor drum stage 8427 Compressor stall 8428 8429 Impeller Impeller inter cooler A heat exchanger installed in between the stages of compressor to cool the compressed air. 11 IS : 7879 ( Part 8 ) - 1987 No. 8430 Term Vanes Refrigerant injection Definition The injection of a refrigerant (for example, water, an alcohol or mixtures thereof ) into the working fluid before, during or after compression to enhance the performance of the engine. Radial or circumferential vanes fitted in the air intake. 8431 Vanes inlet AIR-INTAKE VANES Rotating Toroidal guide-vanes GUIDE- 8432 8433 guide vanes guide vane Curved extensions of the impeller vanes projecting adjacent-to the threat of the air intake casing. A flared annular the incoming ller intake. guide-vane air evenly in an air-intake casing over the entire area of into, or Fuel Supply 8434 and Combustion Systems A device which, with changes in atmospheric `pressure, regulates the flow in the fuel manifold, by varying the delivery of a fuel pump. A device which, with changes in atmospheric pressure, regulates the pressure supplied, and thereby the flow in the fuel manifold, by means of spill through a relief valve. Barometric fuel control BAROMETRIC PRESSURE CONTROL Barostatic BAROSTAT relief valve 8435 8436 Burner A device for injecting a spray Of fuel intO the combustion chamber. This may be fixed or variable orifice type. In American practice the term may include the whole combustion chamber. burner burner A burner orifice. with with alternative a single fuel fuel entries and a single exit orifice. exit 8437 8438 8439 8440 8441 Duplex Simplex Spill A burner entry and a single burner A burner in which a portion of the entering fuel is recirculated instead of passing into the combustion chamber. Combustion in the by-pass air of a by-pass turbine engine to provide additional thrust. chamber or ducted-fan By pass heat Characteristic length The length of a straight tube of constant cross-sectional area equal to that of the throat of the given chamber, the enclosed volume of the tube being equal to that contained within the combustion chamber of the given rocket engine between the injection face and the throat. A 8442 8443 8444 8445 Combustion Flame tube Flame out chamber chamber in which combustion occurs. This may be a simple chamber or contain one or more flame tubes. a combustion cessation chamber, in which combustion A tube within occurs. Unintentional engine. of combustion in a jet or gas-turbine Fuel accumulator A device for storing fuel, during a portion of the starting cycle, in order to augment the flow momentarily when a predetermined fuel pressure has been reached, A device for controlling accordance with pilot engine limitations. ( Fuel ) the fuel supply demand, ambient pipes to an engine in conditions and distributing fuel 8446 Fuel control unit 8447 Fuel manifold feeded manifold A main pipe with a series of branch to the burners. 12 iS : 7879 ( Part No. Fuel Feeder 8448 Term Manifold switch Definition 8 ) - 1987 Fuel pressure A device which ensures that full current is not applied to the electric starter motor until fuel pressure has reached a predetermined figure. An electric discharge ing the turbine, A combined combustion plug for igniting the fuel when for start- 8449 8450 8451 8452 Idling 8453 8454 Igniter Torch plug igniter igniter plug and fuel atomizer when starting the turbine. adjacent combustion initiating or flame from fall- Interconnector Minimum Control Primary pressure valve A pipe connecting tubes. chambers A device which prevents the burner ing below a predetermined value. fuel pressure Valve holes holes Holes through which a portion of the airflow is passed a flame tube for the early stage of combustion. into Secondary Holes through which air is passed into a flame tube downstream of the primary holes to stabilize the flame and to complete combustion. Holes through which air is passed into a flame tube downstream of the secondary holes to dilute the hot gas and so to reduce its temperature. Combustion thrust. after the last turbine stage to provide air additional and the into 8455 Holes tertiary 8456 8457 8458 8459 Exhaust 8460 Reheat AFTERBURNING Return Straight Swirl-vane System Eyelids CLAMSHELL Exhaust cone SHUTTERS flow system A combustion system in which the entering emerging gas flow in opposite directions, A combustion system in which the entering the ffame tube or combustion chamber. flow system air passing Avane used to impart a swirling motion to the air passing into the flame tube or combustion chamber. Two hinged shutters, suggesting eyelids in appearance action; used to control the flow of the exhaust gases jet propulsion engine. and in a 8461 An assembly which leads the exhaust gases from the annular turbine discharge to the jet pipe. It usually consists of two main parts, an inner and an outer cone, mounted concentrically with the turbine wheel. An assembly of stator-blades situated behined the turbine discharge to remove residual whirl frcm the exhaust gases. A shield to protect the rear face of the turbine the heat of the exhaust gases, disc from 8462 Exhaust stator-blades 8463 8464 ,8465 8466 8467 Insulation Jet pipe Jet silencer Serrated Propelling plate A pipe which leads the exhaust gases from the exhaustcone to the propelling nozzle on turbojets. A device incorporated with the propelling the noise from the jet. A jet silence consisting of a nozzle form of radially disposed slots. nozzle to reduce nozzle nozzle whose exit area is in the The nozzle attached to the rear end of the jet pipe or to the exhaust cone or to the by-pass duct to increase the velocity of discharged gases. 13 Term 8468 8469 Convergent Convergent nozzle CONDI-NOZZLE . 8470 Centre-body nozzle PLUG NOZZLE BULLET NOZZLE Ejector shroud nozzle nozzle divergent Definition A propelling nozzle whose cross-sectional progressively towards its exit. area diminishes A propelling nozzle whose cross-sectional area diminishes to a throat of minimum area and increases again towards the exit. A propelling nozzle in which gas passes between an outer skin and an inner body, usually arranged in such a way as to create a convergent-divergent passage. The centre-body may be fixed or axially moveable. A shroud arranged around the exit of a propelling produce an induced flow of air. nozzle to 8471 8472 External expansion A propelling nozzle in which the supersonic expansion occurs wholly or partially downstream of the walls of the nozzle. A propelling nozzle, generating supersonic the expansion occurs completely within nozzle. A propelling introduced expanslon. nozzle into which a second either at the start of or during velocity in which the wall of the gas stream is the supersonic to 8473 Internal expansion nozzle 8474 Two-stream nozzle 8475 8476 8477 Variable-area nozzle Thrust Thrust reverser spoiler propelling A propelling nozzle in which the flow area can be varied obtain optimum engine operating conditions. A controllable device mounted nozzle to reverse the jet thrust. A controllable device mounted nozzle to reduce the jet thrust. at or on the propelling propelling at or on the Miscellaneous 8478 By-pass ratio Terms ln a by-pass or ducted-fan turbine engine, by-pass airflow to the high pressure airflow. the ratio of the or combustion 8479 Diffuser buzz An oscillatory shock motion and airflow associated with the shock system ahead of the inlet; very rapid pressure pulsations are produced, which can affect the behaviour of engines. The revolutions per minute rotor assembly. of the main or other specified a flow of hot gas and 8480 8481 Engine speed Gas generator 1) A gas turbine engine which supplies under pressure for use elsewhere. 2) The high pressure compressor, turbine of a by-pass or ducted combustion fan engine. chamber 8482 Gag turbine pass turbine engines engine by- A gas turbine engine in which a proportion of intake air is diverted from the compressor into a duct such that it by-passes the combustion and turbine sections and is reintroduced into the jet stream. A gas turbine engine in which the compression of the intake air is performed in stages in a number of mechanically separate compressors each of which is driven by a separate turbine. A two-stage compound turbine engine. 8483 Compound turbine engine 8484 Two-shaft engine TWOSPOOL ENGINE 14 IS: No. 8485 Term Definition 7879( Part 8). 1987 Contra-flow turbine A gas turbine engine in which the turbine and compressor bladss are integral or adjacent, and the working fluid flows in opposite directions through the respective passages of the two sets of blades. 8486 turbine Ducted-fan ENGINE TURBO-FAN A gas turbine engine in which a portion of the net energy is used to drive a ducted fan. `It may be front or rear fan and the by-pass airflow may either be mixed with the high pressure or combustion airflow or be discharged directly from the fan. A gas turbine engine in which the turbine driving shaft is not coupled to a compressor rotor. A gas turbine engine in which to a compressor rotor. the output shaft the output is coupled 8487 8488 8489 Free turbine Single engine shaft engine Turbojet JET TURBINE ENGINE A gas turbine engine in which the net energy available is utilized by the air or hot gas solely in the form of a jet issuing through a propelling nozzle. A gas turbine engine in which is used to drive a propeller. a proportion of the net energy 8490 Turboprop engine PROPELLER TURBIN ENGINE Turboshaft engine E 8491 A gas turbine engine in which a proportion of the net energy is used to drive a main output shaft other than driving a propeller or ducted fan. Lift derived from the downward engine or power-driven rotor. displacement of air by a jet 8492 8493 8494 8495 Powered Jet lift Lift fan lift Lift for the purpose of V/ST OL derived or vectored thrust engines. A fan on VTOL aircraft, installed vertical, solely to provide lift. interwith from the lift engine its axis substantially Pulse jet engine mittent jet engine An engine producing a pulsating jet by burning fuel in air in such a way that the compression due to forward speed is augmented by the pressure waves within the unit, the pulsation being produced by intermittent closing of the intake or by other means. A form of blade stall in around the blade row. which the stall condition moves 8496 Rotating Thrust stall 8497 Net ( standard ) thrust The force in the direction of motion deducted from the resolved components of the normal pressures on the inside of the pre-entry stream tube and on the internal surface of the duct. The net thrust obtained from a gas turbine using after burning ( reheat ). engine without 8498 8499 Dry thrust Gross ( standard ) thrust The force which occurs in a gas turbine engine by the reaction to the momentum of exhaust gases at the exit place of the propelling nozzle inclusive of the pressure thrust. In a jet propulsion engines, the net thrust available translational motion under prescribed conditions. with no 8500 8501 Static thrust thrust Vectored Net thrust obtained in the specified direction of jet nozzle(s) of gas turbine engine through which compressed air and! or the exhaust gas is flowing. Thrust developed by engine ted into the engine. per unit mass flow of air induc- 8502 Specific thrust 15 IS: 7879 (Part No. 8503 Reheat 8) - 1987 Term thrust Definition Augmented thrust of an engine obtained by the introduction and burning of fuel between the engine turbine and the jet pipe propelling nozzle utilising the unburnt oxygen in the exhaust gas. thrust Net thrust available conditions. at ground idling speed under prescribed , 8504 Ground idling EXPLANATORY This Indian Standard is one of the series to aeronautical and astronautical fields. The are: IS : 7879 ( Part IS : 7879 ( Part 1 )-I975 2 )-I975 Glossary Glossary aircraft Glossary Glossary namics of of NOTE of Indian Standards on glossary of terms pertaining other Indian Standards published in this series and and astronautical astronautical terms: terms: terms: Part Part 1 General 2 Motion of aeronautical aeronautical IS : 7879 ( Part 3 )-1975 IS : 7879 ( Part IS : 7879 ( Part IS : 7879 ( Part 4 )-I980 5 )-I982 6 )-I978 of aeronautical of aeronautical and astronautical and astronautical Part 3 Structure Part terms: terms: terms: terms: operations relating Part Part 4 Aerody- Glossary of aeronautical ( heavier-than-air aircraft Glossary of aeronautical and astronautical 5 Aerodynes 6 Space 7 Air terms traffic ) and astronautical and astronautical technical terms IS : 7879 ( Part 7 )-I984 IS : 10041-1981 The including present standard gas turbines. Glossary of aeronautical and ground services A Glossary of Terms definition - Part Airlines of provides standard technical to power plant The general arrangement of the terms is alphabetical. However, in certain case, the relative terms have been given together under a heading or general definition. Where two or more synonymous terms are in use, the term which is favoured IS given first with the rniention that it should gradually displace the others. Each term has been assigned a 4-digit number. The first one ( or two) digit, place, represents the part number. This part number with the following digit place represents the section. The last two digits represents the position of the section, thus, the term 8215 is the 15th definition of Section 82 which is Part 8. In the preparation of this Indian Standard assistance has been derived nautical and astronautical terms, issued by the British Standards Institution. in the thousandth in the hundredth definition within a BS : 185 `Aero- from 16 Printed at New India Printing Press. Khuria. India